Year	Percent
1965	30.79976
1966	33.42535
1967	29.39762
1968	35.36751
1969	33.02048
1970	34.15221
1971	36.36228
1972	40.74226
1973	42.74561
1974	53.69124
1975	64.9329
1976	70.98275
1977	77.7584
1978	69.20945
1979	72.32153
1980	76.11181
1981	88.90034
1982	85.28881
1983	73.48985
1984	71.19401
1985	70.52704
1986	49.44246
1987	53.88123
1988	59.75597
1989	76.59422
1990	88.07684
1991	83.74287
1992	84.15973
1993	85.35739
1994	77.03111
1995	81.24925
1996	88.17383
1997	81.94653
1998	71.15479
1999	68.09336
2000	76.78102
2001	79.81559
2002	81.87883
2003	86.55643
2004	105.7052
2005	117.56172
2006	111.26185
2007	113.41871
2008	113.47476
2009	86.52854
2010	85.49316
2011	93.39835
2012	92.56904
2013	87.72147
2014	87.40536
2015	75.45265
2016	69.52087
2017	68.66314